Grinding machine



J an14,1936. 1 1.. 51.000 ETAL 2,027,621

I GRINDING tacama Filed Aug. 8, 1953 G ShQQtS-SIIBQt 1 J HaroldL. Blood Alfred PBurn a, MZM/ J 1 36- H. 1.. BLOO 2+ m. "2,027,6 1

GRINDING MACHINE Filed Aug. 8, 1953 6 Sheets-Sheet 2 III/[Ill am. m.

L P w T B rns Jan. 14, 1936.

H. L. BLOOD ET AL GRINDING MACHINE I Filed Aug. -8, 1933 6 Sheets-Sheet 3 3mm Harold I. Blood Alfred E Burns Jan.,14,1936. H. BLOOD ETAL 2,027,627 I GRINDING MAQHIQNEI .Filed Aug. .8, 1933 6 Sheets-Sheet 4 .Harold.C BloOd a 7 I fllfred PBurns Jan. 14, 1936.

' H. 1.. BLOOD ET AL 6 Sheets-Sheet 5 n m 5. 5 0 Q w '2 m2 3 1 H ya m /8 2 m7 0 2 w 6 m. 7

v v a 1 6 h 9 o 4 a u 3 4 7 1 H H 1. w. 1 1am n? A m H mm W 1 1 7 m as. a 2 a a 1 HarolJLDLood F ALfredFfBurns W W4/ Fatenteoi Jan. id, 11936 res attract carcinoma ma name L. mood. and Alfred 1?. Burns; Worcester,

Mass-., assignors to The lliieaidl Machine Comh m, Worcwter, Mass, a corporation of Massa= chusetts Application August 8, 1933, Serial No. 684,210

25 Claims. on. 51-95 'l'he present invention relates to agrinding machine for the reduction of workpieces to a predetermined size, and it is particularly applicable to machinesfor grinding the internal surfaces of sleeves, bushings, or like articles.

In grinding machines of the type disclosed in United States Letters Patent No. 1,682,672, issued August 28,1928 to Guild, and Patent No. 1,731,719 issued October 15, 1929 to Kempton and Gallimore, the crossfeed movement by which the grinding wheel is fed against the workpiece is procured in response to the longitudinal reciprocations of the table. This type of crossfeed movement results necessarily in a step-by-step crossfeed movement so that the pressure of the grindmg wheel against the workpiece is not uniform.

- It is accordingly the principal object of the present invention to provide a mechanism by which the crossfeed movement may be uniform and may occur at a predetermined rate during the grinding operation. The invention also provides for varying the rate of crossfeed movement during the grinding operation.

In machines of the type-disclosed in the above cited patents, the crossfeed movement is automatically discontinued during the runout of the table for a dressing operation which occurs durin the grinding operation. In providing for a uniform crossfeed movement,- instead of the step-bystep crossfeed movement of the prior constructrons, use is made of fluid pressure actuated mechanisms which operate independently of the table movement, and .accordingly the crossfeed movement is not discontinued when the table is given an extended movement forthe dressing operation. It is accordingly a further object of the present invention in connection with a crossfeed movement actuated by fluid pressure responsive means to provide for a-ternporary cessation of the crossfeed movement while the dressing operation is taking place. 1

In the use of a centerless work-supporting structure of the type disclosed in the Einstein Patent No. 1,772,932, issued August 12, 1930, it is desirable to provide a structure for removing the finished workpiece from within the work-supporting structure and inserting an unground workpiece therein. The copending Highberg application Serial No. 266,287, filed March 31, 1928, 'now Patent No. 2,003,713, dated June 4, 1935, provides for the discharge of a finished workpiece and the positioning on an unground workpiece within the work-supporting and rotating structure and involves an extended movement of the pressure wheel forming a part of the work-supthe line 9-9 of Fig. 8.

porting structure which permits the finished workpiece to drop from within said work-supporting structure. No ejecting or discharge mech-- anism for positive removal of the workpiece is provided. The copending application of Einstein, 5 Booth and Haas, Serial No. 374,556,fiied October 25, 1932, discloses an ejector mechanism which is actuated by fiuid under pressure and involves a downward movement of the ejector mechanism into engagement with the workpiece and subse- 1 quent upward swinging movement ofthe ejector for removal of the workpiece, an unground workpiece falling, by gravity,.intogrinding position.

The present invention is, in certain respects, an improvement on these patents and copending applications by the provision of an. ejector which procures a positive ejection of the workpiece radially of the work-supporting structure and causes the unground workpiece to be properly positioned within the work-supporting structure.

Other and further objects and advantages of the invention will appear from the following detailed description taken in connection with the accompanying drawings in which:---

Fig. l'is a front elevation of a machine embody-'- ing the invention. I

Fig. 2 is a vertical sectional view substantially along the line 22 of Fig. 1 and showing the grinding wheel in operative position.

Fig. 3 is a fragmentary elevation showing the gage structure, parts being broken away to show more clearly the construction.

. Fig. 4 is a vertical sectional view showing the driving means for the regulating wheel and the structure for actuating the ejector.

Fig. 5 is an end elevation of the structure of Fig. 4.

Fig. 6 is a vertical section along the line 6-6 of Fig. 1 showing the crossfeedmeehanism.

Fig. 7 is a vertical section substantially along the line 'I-l of Fig. 6.

Fig. 8 is a sectional view substantially along the line 8-8 of Fig.6 with parts broken away.

Fig. 9 is a vertical section substantially along' Fig. 10 is an enlarged elevation of the control structure mounted on the front of the machine.

Fig. 11 is a fluid pressure diagram.

Like reference characters refer to the different figures.

Referring first to Fig. 1, the machine providesv the usual reciprocatory table 3 provided in an internal grinding machine; either the grinding wheel or the work to be ground is carried. on said table, the reciprocations of. the latter operating 55 like parts in in either case to produce a relative translatory movement between said grinding wheel and the workpiece. In the construction shown, the table supports and carries a workhead 2 and the wheelhead 3 is mounted on a bridge 4 which spans the guideways, not shown, provided by the base 5 .of

the machine for the movements of the table I.

The grinding wheel 6 is carried on a spindle I journaled in the wheelhead 3 and is suitably rotated at a high rate of speed by any well-known mechanism, not shown. The workpiece a, Fig. 2,

, is mounted in the work-supporting structure on issued to Heald and Guild April 27, 1926. It is suflicient to note for the purpose of thepresent application that reversal of the table is procured at each end of the normal working stroke by spaced adjustable dogs 8 and I which are carried by blocks II and i2 adjustably mounted on the table I and which are adapted alternately to engage and move a reversing member l3. The latter provides spaced upwardly projecting lugs l4 and I (see Fig. which, during the grinding operation, when the workpiece is reciprocated back and forth over the grinding wheel, are situated in a position to be engaged by the dogs 8 and i0 respectively. The movements of the member l3 procure reversal of the movements of the table I through suitable mechanism to be described later.

positioned. The valve casing has outlet ports 2| and 22 connected by pipes '23 and 24 to the right and left hand ends respectively of a cylinder 25 mounted within the base of the machine. A piston 26 is slidable within the cylinder and has a projecting piston rod 21 which is secured to a dependinglug 28, Fig. 4, on the under side of the table I. The reversing valve alternately directs fluid under pressure to opposite emls of the cylinder for urging the table I alternately to the right and tothe left. At the same time, fluid exhausts from the opposite end of the cylinder fhroiuagh an exhaust port 29 provided by the cas- As shown in Fig. 11, the left hand end of the cylinder is provided with spaced ports 30 and 3|. The port 30 at the extreme end of the cylinder is connected by a channel 32 in which a ball check valve 33 is positioned to a channel 34 which connects the end of the pipe 24 to the port 3|.-

The latter is spaced from the left hand end of the cylinder sufficiently to be covered and closed by the piston26 before said piston reaches the left hand end of the cylinder. Thus, as the piston moves into the position shown, and closes the port 3 i further exhaust of fluid from the left hand end of the cylinder is cut off, as the ball check valve 33 prevents discharge of fluid through the port 30. The table is thus brought to rest under the cushioning action of the fluid locked in the end of said cylinder. When the reversing valve 20 is shifted ressure enters the left hand end of the cylinder aoa'ma'r past the check valve 33 for shifting thepiston 28.

The reversing member I3 is connected to the reversing. valve 20 for actuating said valve in response to the shifting movements of said member. As best shown in Fig. 10, the forward end of the reversing valve 20 has secured thereto an arm 35 which supports a pin 35 in spaced relation to the center line of the valve. Said pin is positioned between spaced projecting lugs 31 and 38 on the end of an arm 40 secured to a shaft 4| journaled in the control box 42 on the front of the machine. The reversing member I3 is also secured against turningf movement on the shaft 4| so that said member and the arm 40' move as a unit. The arm 40 has a V-shaped'projecting portion 43 which engages with a corresponding V-shaped lug 44 on the end of an arm 45 pivotally mounted on a pin 45 carried by a bracket 41 secured within the control box. The arm 45 is urged upwardly into engagement with the V- shaped portion 43 by a spring 48.

As will be apparent from the drawings, the spacing between thelugs31 and 38 is materially greater than the diameter of the pin 36 to provide a lost motion between the arm 40 and the reversing valve. As the arm 40 is rocked clockwise by the reversing dog 8, the V-shaped portion 43 slides along the side of the V-shaped lug 44 with which it is in engagement until the points of the V-shaped portion and lug pass each other.

The arm 40 is then moved positively clockwise a further distance by the action of the spring 48 and procures a shifting movement of the valve 20. A positive reciprocation of the table is thus procured in response to oscillation of the reversing member l3 by the reversing dogs 8 and i0. I

For shifting the reversing valve manually in setting up the machine, the arm 40 carries a pin 50 which is positioned between spaced arms 5| and 52 provided by a plate 53. The latter is secured to a shaft 54 journaled in the control box. and said shaft projects through the cover 55, Fig. 1, of the control box and carries on the forward end thereof a lever 56 which provides for manual turning movement of the shaft. Oscillation of the plate 53, as will be apparent, will shift the arm 40 and accordingly procure a turning movement of the reversing valve. The arms 5i and 52 are spaced apart a distance substantially greater than the diameter of the pin 50 to permit the arm 40 to rock without a-corresponding movement of the lever 56.

The crossfeed movement between the workpiece and the grinding wheel is obtained by transverse movement of the wheelhead 3 on the bridge 4. The wheelhead is mounted on a crossslide, not shown, and movement of said crossslide is obtained by rotation of a crossfeed screw 51, Fig. '7, which engages an internally threaded portion, not shown, of the cross-slide. Said crossfeed screw carries a gear 58 on the forward end thereof, which meshes with a pinion 60 secured against turning movement on a shaft 6| journaled in a casing 62 in which the crossfeed mechanism is positioned. The casing 82, as best shown in Fig. 1, is secured to the forward end of the bridge. The pinion 80, during the crossfeed movement of the table, is rotated in unison with a ratchet wheel 63 which is positively actu-- ated by fluid under pressure as hereinafter described. The rotation of the pinion 3|! procures, through rotation of the screw 81, a movement of the grinding wheel transversely of the machine.

to cause the wheel to cut successively deeper and deeper into the workpiece.

The shaft ti has journaled thereon an annular member or sleeve to having an'integral pinion 65, and a vertically extending rod 68, Fig. 1, has rack teeth Ell thereon which are held in engagement with the teeth on the pinion by a roller 68 journaled on a pin it secured to the casing 62. The rod 66 is positively reciprocated vertically for procuring. a crossfeed movement during its upward movement and a subsequent retraction of the crossfeed movement when the rodmoves downwardly.

The sleeve 6% has a flange ii thereon with a tapered peripheral surface 72 which engages a correspondingly tapered internal surface 73 of an annular member it journaled on the member t l. A nut 'l5 which engages a threaded portion of the sleeve 64 procures a positive engagement between the surfaces I2 and T3 to prevent a relative turning movement between the sleeve 64 and the annular member it.

The annular member it has spaced studs 75 and Ill secured by nuts l8'and to said memher, and said studs provide pivotal supports for pawls Bi and 82, Fig. 8, respectively. Said pawls are normally maintained resiliently in engagement with the ratchet wheel 61! by a spring 83. The pawl 82 procures clockwise turningmovement of the ratchet wheel in response. to a corresponding clockwise rotation of the gear 55 and the pawl procures counterclockwise turning of the ratchet wheel when the gear 85 is turned counterclockwise. When both pawls are mengagement with the ratchet wheel, the latter rotates as a unit with the gear 65.

During the crossfeed movement of the grind-- mg wheeLwhich involves a clockwise rotation of crossfeed movement continues, however, under the action of pawl 82, and this movement carries the pin 8E onto the shield 85. During a subsequent retraction of the crossfeed movement by a counterclockwise turning movement of the sleeve 84, however, the annular member I4 turns counterclockwise relative to the ratchet wheel 63,

sincethe pawl BI is inoperative, unt'l the pin I 84 is carried counterclockwise out of engagement with the shield 85. Said pawl is then returned into engagement with the ratchet wheel 63 by the spring 83, and said wheel 63 then rotates as a unit with the annular member and the sleeve 64 during the remainder of the retracting movement. The relative turning movement between the annular member 14 and the ratchet wheel 63 during the retracting movement provides a compensation for the reduction in size of the grinding wheel. as will hereinafter appear.

Since the movement between the ratchet wheel 63 and the annular member M, which provides the compensation for the reductionin size of the grinding wheel, is dependent upon the position of the shield 85 relative to the pin lit at the end of. each grinding operation, said shield is adjustable so that the extent of the compensatory movement may be varied in order to correspond approximately to the reduction in size of the grinding wheel. Referring now to Fig. 9, the shield 85 is carried by a plate 86 secured against rotation on a shaft 81, the latter having secured to its opposite end a knurled nut 88. The casing tz-is prothe annular member.

'end of said shaft.

vided with an arcuate slot.90 concentric to the shaft 6i and this slot receives a sleeve 9! having a shoulder 92 which engages the inner surface of the casing. A nut 93 on a threaded portion of the sleeve engages the outer surface of thecasing for clamping the sleeve in fixed position in the arcuate slot. The shaft 81 is slidable within the sleeve 9i and a spring 94 within the sleeve, and surrounding the shaft 81 urges the latter toward the left, Fig. 9, to urge the knurled nut 88 against 'the end of said sleeve, thereby maintaining the .The knurled nut 88 which is positively secured to the shaft Bl has a projecting pin 96 engaging a recess in the sleeve ill. The shield 85 is with=- I drawn from operative position bymovement of Y the nut 81 to the right, thereby drawing the shield to the right therewith, and subsequent turning of the nut to cause the pin 96 to engage the end of the sleeve 9i in a position spaced from the recess which normally receives said pin. The shield is thus retained in inoperative position, when desired, to avoid any compensatory movement. The

operative position of the shield 85 may be readily.

adjusted by loosening the clamping nut 93 and shifting the position of the sleeve ill in the slot 9t.

In setting up and adjusting the machine for the grinding of a predetermined size of workpiece, it is desirable to provide for rotation of the annular member it manually relative to the ratchet wheel 63. For this purpose, the annular member I4 has a shaft 971, Figs. 6 and 7, journaled therein to the inner end of which is secured an eccentric disc 98, in a position for engagement with projecting lugsI00 and MI, Fig, 8, on the pawls 8| and 82 respectively. The forward end of the shaft 91 is provided with a pinion I02 for engagement with a series of gear teeth I03 provided by-a ring I 04 which is rotatable on a shoulder I05 on the annular member l4 and is held against removal therefrom by washers I06 on screws I0'|.engaging A manual turning move ment of the ring I04 positions the eccentric disc in engagement with the lugs I00 and II, thereby withdrawing both of the pawls 8| and 82 out of engagement with the ratchet wheel. The ratchet wheel 63 is then free to turn independently of the annular member l4.

The annular member" also carries a cam I08 which becomes operative during the grinding op- -movement of the annular member 14 on said.

sleeve 64. The position of the cam Illa-at the beginning of the grinding operation is thus easily adjusted and the rate of crossfeed movement is accordingly reduced at the desired point in the grinding operations A crossfeed movement is manually procured by a hand wheel I I0 having a hub whichengages a' portion III of the shaft BI and which is clamped against a. shoulder 2 on said shaft by 'a'clamping nut II3 engaging the feed shaft 57. During the manual crossfeed movement the pawls 80 and BI are-withdrawn from the ratchet wheel 63, as above pointed out.

I Rotation of the hand wheel turns the pinion 60- and thus rotates the cross-.

The rod 66 by which the gear 65 is rotated, for procuring the crossfeed movement, is actuated by fluid under pressure. Referring to Fig. 11, the rod 66 is a continuation of a piston rod I I 4 secured to a piston II5 slidable in a cylinder II6 secured, as shown in Fig. 1, to the base 01' the machine. Fluid under pressure from the pump I6 passes through a pipe I I1 to a channel I I8 in a casing I having a longitudinal bore I2I in which a valve member I22 is slidable. The channel II8 intersects the bore I2I and a channel I23 in the casing I20 also intersects the bore at a point substantially opposite to the intersection of the channel H8. The channel I23 is connected by a pipe I24 to a channel I25 in a casing I26 having a longitudinal bore I21 in which a valve member I28 is slidable. The channel I25 intersects the bore I21 substantially opposite to the intersection of said bore with a channel I30 in which a manually controlled throttle valve I3I is positioned. The channel I30 intersects a channel I32 which opens into the bore I21 at a point spaced from the intersection of the channel I 25 therewith. The casing I26 also has a channel I33 therein which intersects the bore I21 and is connected by a pipe'I34 to a valve casing I35 in which a valve I36 is positioned. A channel I32 intersects the channel I30 and also intersects the bore I21 substantially midway between the openings from the channels I30 and I32 into said bore.

With the valve members I22 and I28 in the positions shown, these being the positions of said valves at the beginning of the grinding operation,

fluid under pressure is admitted to the pipe I34 from the pump by passingaround a reduced portion I31 of the valve member I22 which provides a fluid connection between the channel H3 andthe channel I23 and around a reduced portion I38 oi the valve member I28 which provides a fluid connection between the channel I25 and the channels I32 and I32. A second reduced portion I40 on the valve I'28 spaced from the reduced portion I36 by a full-size portion I4I provides for fluid connection between the channel I32 and the channel I 33. Fluid under pressure thus enters the casing I35, but the flow of fluid through said casing to the cylinder II6, to which said casing gonnected, is normally prevented by the valve Thecasing I35 has an outlet port I42 connected by a pipe I43 to a port in the lower end of the cylinder II6, said port b'eing normally closed by the valve I36. The upper end of the cylinder is connected by a pipe I44, and a pipe I45 connecting therewith, to a channel I46 in the casing I20. A channel I41 which intersects the channel I46 also intersects the longitudinal bore I2I and fluid connection is normally provided from the channel I41 to an exhaust channel I48 in the cas ing I20 by a reduced portion I43 ofthe valve member I22ea'djacent the right hand end thereof. The valve I36 is moved manually to the left, Fig. 11, against the tension of a spring I50 positioned "within the casing I35, by pressure on a button I5I on the end of the valve stem I 52 of the valve I36,

the grinding wheel relative to the workpiece.

During upward movement of the piston II5, fluid above said piston exhausts through the pipe I45 to the exhaust channel.

The valve I36, which is manually controlled, as above stated, provides for a rapid transverse movement of the grinding wheel to bring the grinding wheel and workpiece into operative position. During the normal operation of the machine, while the workpiece and grinding wheel are in engagement, the crossfeed movement occurs at a predetermined slow rate oi. speed by throttling the flow of fluid to the lower end of the cylinder II6. Referring again to Fig. 11, the pipe I34 is connected by a branch pipe I54'to a channel I55 in a casing I56. The channel I55 intersects a vertical channel I51 and the latter intersects at its upper end a bore I58 in which athrottle valve I60, for controlling the rate of crossfeed movement, is positioned. The bore I53 is connected by a short channel I6I to a vertical bore I62 in the casing I56 in which a valve I63 is positioned, the latter being normally held in the position shown by a spring I64 positioned in the lower end oi. the bore I62; The valve I has a short longitudinal bore I65 in the end thereof and a short lateral channel I66 intersects the bore I65 and provides fluid connection from the channel I51 into said bore. Turning movement of the valve I60 varies the size of the opening between the channel I51 and the channel I66 for controlling the amount of fluid passing therethrough.

The longitudinal-bore I 62 has an outlet port I61 connected by a pipe I68 to the pipe I43 which leads to the lower end of the cylinder I I6. Fluid connection is normally provided between the channel I6I and the port I61 by a reduced portion I10 of the valve I63. As fluid under pressure is normally admitted to the pipe I34, as above pointed out, fluid under pressure also, enters the by a short pipe I15 to the pipe I68. The valve I12 has a bore I 16 longitudinally therein, and a short transverse channel I11 in said valve provides fluid connection from the channel I51 to the bore I16. Turning movement of the valve I12 varies the size of the opening into the channel I11,

thereby determining the amount of fluid entering said bore. Fluid connection is normally provided between the channel I13 and the port I14 by a reduced portion I18 of the valve .I 63, said reduced portion being spaced from the reduced portion I10 by a full-size portion I80. The valves I 60 and I12 have knurled knobs HI and I02 respectively on the outer ends thereof to provide for manual adjustment of said valves, said knobs being accessible at the side of the machine, as shown in Fig. 1.

During the preliminary or rough grinding operation, fluid under pressure enters beneath the piston I I5 through the valve I 60 and also through the valve I12, the volume of fluid being adjusted by shifting the position of the valve I60. During the grinding operation, as the crossieed movement continues, the cam I08, above referred to, is advanced clockwise into engagement with the upwardly projecting end I83 of the valve I53 and table. An adjusting screw 2M which is held procures a downward movement of said valve. By this downward movement, the opening from ,the channel it! intothe' port it! is closed by a full-size portion E84 of said valve above the reduced portion l'lil, thereby cutting 01f the flow of fluid through the valve Hit. The crossfeed movement during the remainder of the grinding operation occurs at a materially slower rate of speed valves I22. and i128, so far as they control the movements of the-table, are fully described in the copending Blood and Burns application, Serial No. 681,334, filed July 20, 1933, now Patent No. 2,011,705, dated August 20, 1935. For the purposes of the present application it will be sufficient to note that the casing H20 (referring to Fig. 11) has a channel ltlispaced from the channel M8 and connected by a pipe I86 to a'channel it? in a casing its having a, longitudinal bore i 90 therein in which the main throttle valve 119i is positioned. The latter has a longitudinal recess i at therein which is open to the inner end of the bore H92 and the end of said bore is connected by a pipe 893 to the inlet port i! of the reversing valve casing it. The throttle valve lei has a rectangular notch we adjacent the intersection of the channel it? with the bore let to provide fluid connection between the channel 987? and the recess in the valve.- By the rectangular shape of the notch, the flow of fluid from the channel i8? is unthrottled regardless of the adjusted position between the reduced portion i3? and the reduced portion M9. 1 g

' The casing i26 has a channel I96 spaced from the channel 925 therein, and said channel We is connected by' a pipe I91 to a channel 998 in the casing i813. The throttle valve H99 is provided with a V-shaped notch 200 adjacent the intersection of the channel I98 with the bore H92, thereby providing for adjustment of the flow of fluid from the channel I98 into the recess i912 in the valve by a turning movement of said valve. The latter has a forwardly projecting valve stem 20! which projects through. the coverplate of the control box 42 on the front of the machine and has a lever 204 on the end thereof by which said valve may be manually positioned. Fluid connection is normally provided between the channel I25 and the channel I96 inthe casing 126 by the reduced portion I38 of the valve I28 -=so'that the normal movement of the table occurs work-supporting wheel 201 mounted on a slide 208 adjustable on a bracket 2) secured to the against axial movement in a lug 2 i 2 on the brack et 2H1 engages the slide 208 to provide for adjustment of the position of the supporting wheel. The workpiece a is held in engagement with the regulating'and supporting wheels by a pressure wheel M3 on a shaft M3 in the end of an arm 2M which is secured against rotation ona shaft 2i5 journaled in the workhead. The pressure wheel is resiliently held against the workpiece as will hereinafter appear. The spindle 285 is positively rotated by a worm gear 288 thereon engaging a. worm 2 H on a positively rotated shaft 21a which, in the construction shown, is a continuation of the shaft of the driving motor 2H9.

Rotation of the wheel 2% procures acorresponding rotation-of the workpiece a by engagement with the periphery thereof, this rotation of the workpiece being clockwise as seen in Fig. 2. The workpiece is thus supported and rotated on the cylindrical outer surface thereof during the grinding operation.

As shown in Fig. 3, the workpiece is held against axial movement by a rotating backing plate 220 which is rotatable about an axis coinciding subto the axis of the workpiece.

The grinding operation is under the control of gage members 223 and-22d, Fig. 3, which are carried on the end of a gage rod 225 longitudinally slidable in the workhead. The gage rod extends through an opening 226 centrally'of the backing plate 220 so that the gage members 223 and 22 3 are supported in alinement with the bore of the workpiece. The outer or left hand end of the gage rod 225 has an arm 22'i journaled thereon and supported against axial movement thereon by bearing members 228. The lower end of said arm is secured against movement on the end of a rod 238 which is longitudinally slidable in a bore 23i in the workhead. The right hand end of the rod 230 projects tothe right beyond the workhead as shown in Fig. 1 and is normally in alinement. with the head of an adjustable screw 232 mounted in a bracket 233 on the bridge 4. A spring 236 in an opening 235 within theworkhead surrounds the rod 230 and engages, at one end, a sleeve 233 on said rod, said sleeve being suitably held against movement on said rod. The other end of said spring engages a portion of the workhead for normally urging the rod 230, which is parallel to-the gage rod 225, to the right, thereby urging the gages into contact with the end of the workpiece.

The rod .230 carries adjacent the arm 22'! a. forwardly projecting arm 23?, in the outer end of which is positioned an adjustable screw 238 held in adjusted position by -a locking-nut 240, said screw, by its movement, controlling the progress of the grinding operation. At' the beginning of the grinding operation, the bore of the workpiece beyond the normal'right hand limit of its movement, a distance corresponding to the thickness of said roughing gage. This extended movement resulting from entry of the roughing gage within the workpiece procures a separation of the workpiece from the grinding wheel for a dressing opchine and which controls the grinding opera-.

tion, The control mechanism is fully disclosed in the copending above cited application of Blood and Burns, Serial No. 681,334, filed July 20, 1933, now Patent No. 2,011,705, dated August 20, 1935. It is sufllcient to note, for the present application, that, as best shown in Figs. 1 and 10, a lever 24!, which is journaled on a shaft 242 positioned in the control box 42 has a depending arm or latch 243 which normally engages a notch 244 provided in a lug 245 on a depending arm 246 joumaled on a shaft 241 in the control box. Said arm is urged counter-clockwise by a spring 248 which is positioned within a recess 256 in a bracket 25l mounted in the control box, one end of said spring engaging the inner end of the recess and the other end of said spring engaging said arm. A bell crank lever 252 which is journaled on the shaft 241 has a depending arm 253 which engages a pin 254 on the arm 246. The other arm 255 of the bell crank lever 252 projects upwardly between the lugs 14 and IS on the reversing member 13 and is provided with a cam surface for engagement with the reversing dog Hi which is pivotally mounted on a pin 256 in the block l2.

'mechanism. During the preliminary or rough grinding operation, the movement of the adjustablescrew 238 to'the right is limited by engagement of the roughing gage 223 with the end of the workpiece, as above stated, and the end of the adjustable screw approaches but does not rock the upwardly projecting arm of the bell crank lever 262. Upon entry of the roughing g e within the workpiece, however, the resultant extended movement ofthe gage members to the right shifts the end of the screw 238 into engagement with the lever 262" to procure a slight turning movement thereof, thereby moving the horizontal am 263 downwardly into alinement with the end of theupwardly projecting arm 251 of the lever 24!.

As the table I moves to the right, following the entry of the roughing gage within the bore of the workpiece, the end of the arm 263 engages and rocks the upwardly projecting arm 261 to procure a clockwise turning movement of the lever 24!, elevating the latch 243 of said lever out of engagement with the notch 244 provided on the arm 246. When the latch is disengaged from the notch, the depending arm 246 moves to the right under the action of the, spring 248, thereby rocking the bellcrank lever 252 to elevate the upwardly extending arm of said lever into alinement with the reversing dog l0. As the table moves to the left the reversing dog In is held out of engagement with the lug l5 by the arm 255, so that said table moves beyond its normal operative position to operative position in alinement with the grinding wheel for engagement therewith during the extended movement. The fluid pressure mechanism for actuating the dressing tool, which is fully disclosed in the Heald and Guild Patent No. 1,779,094, issued October 21, 1930, will be described later in connection with the fluid pressure mechanism. On the return movement of the table to the right into operative position following the dressing operation, a roller 266, carried by the support for the dressing tool, engages a cam, not shown, on the back of the bridge 4 for returning the dressing tool to inoperative position.

After the dressing tool has passed the grinding wheel during the movement of the table to the left, a reversing dog 261 pivotaliy mounted on a pin 268 in a block 210 adjustably secured to the table engages a portion 21| of the lug i 5. The portion 211 projects above and forwardly of the main portion of the lug engaged by the dog l6, and the upper end of the arm 255 in raised position, as a result of the swinging movement of the depending arm 246, does not elevate the dog. 261

212, Fig. 10, pivotally mounted on a pin 213 in said block. A portion of said dog engages a shoulder 214 on the block 216 to prevent clockwise movement of said dog from the position shown.

During the extended movement of the table to the left, the depending dog 212 engages the upwardly extending end of the arm 255 and is swung counterclockwise on the pin 213 without affecting the position of said arm; on the return movement of the table to the right, however, said dog engages the upper end of the arm 255 and returns said arm to the position shown in Fig. 1 with the upper end of said am out of alinement with the reversing dog It. Downward movement of the 255 also returns the depending arm 246 to its original position where it is retained by a latch 216 plvotally'mounted on a pin 216 on the depending arm. s

Referring again to Fig. 10, a stud 211 mounted in the control box 203 prov-ides a support for a lever 218 having a counterweight 266 atone end and a projecting lug 28l which engages with a bracket 25l for supporting said lever in the position shown. A pin 232 in a projecting lug 233 on the lever provides a support for a member 2%, a portion of which engages said lever to prevent clockwise turning movement of said member beyond the position shown. Duringthe extended movement of the table to the left for the dressing operation, a projection 285, Fig. l, on the end of a bar 285 carried by a block 287 on the table en gages the upwardly extending end of the member 284, with which said projection is in alinement, and procures a counterclockwise turning movement of the lever 278. During the return movement of the table to the right, the projection 265 engages and rocks the member 2351 without aiiecting the position of the lever Z'Id.

The lever EIII has a pin 288 to which a rod IIIIII is connected and the lower end of said rod engages the end of a set screw 2% adjustably positioned in one arm of a lever 232. Said lever is pivotally mounted on a stud 293 in the control box and has a notch 2% in the upper surface thereof which provides a locking surface 235 for engagement with a projecting portion 2% on the latch 2'I5. Said latch has a depending end portion 291i engaging with the lever 292 just above the stud 293. In addition to the notch 2%, the lever 232 has a notch 29% on the under side thereof which engages with the left hand end of the valve member I22, Fig. 11, to prevent movement of said valve to the left. Upon counterclockwise turning movement of the lever 218, the right hand end of the lever 292 is elevated to raise said notch out of engagement with the end of said valve. The latter then moves to the left automatically, as will be pointed out hereinafter, to engage with a second and lower notch 299 in said lever. Said lever 292 is then supported by the end of the valve member I22 in the position shown in Fig. 10 and a return movement of the depending'arm 256 to the original position of Fig. 1, in response to engagement between the dog 2'I2-and the upper end "of the arm 255, positions the projecting portion 2% of the latch in engagement With'the surface 295 in the leverv 292 so that the depending arm 2% is retained substantially in the position of Fig. 1 during the remainder of the grinding operation.

'Iheswlnging movement of the depending arm 2436 to the right, above referred to, also procures a shifting movement of the valve member I28, Fig. 11, to the right for reducing the rate of movement of the table during the dressing operation, and for temporarily discontinuing the cross? feed movement. The arm 246 engages, at its lower end, in a notch 300 provided by said valve member. As shown in Fig. 11, fluid connection prior to the dressing operation has been provided directly between the channels I25 and I96 in the casing I26 by the reduced portion I38 of the valve I28, so that the rate of movement of the table is determined by the setting of the main throttle valve I9I. Upon shifting movement of the valve I28 to the right by the arm 246, a full-size portion 30I of said valve cuts off the flow of fluid from the channel I25 directly to the channel I95 and directs the fluid through the channel I30 past the auxiliary throttle valve I3I, and thence through the channel I32 to the channel I96, so that the amount of fluid entering the cylinder 25 is limited by the setting of said auxiliary throttle valve I3I which reduces the flow of fluidto an extent much greater than the reduction of flow by the main throttle valve I9I.

During the same movement of the valve I28 the channel I33, thereby preventing any fluid from entering the cylinder lit beneath the piston I I5 which procures the crossfeed movement, and the crossfeed movement is accordingly discontinued during the dressing operation while the valve I28 is in its right hand position. The crossfeed movement-is again started when the valve member I28 is returned to the position of Fig. 11 which occurs during the return movement of the table to operative position after the dressing operation.

As above stated, shifting movement of the valve I28 to the right also procures a movement of thedressing tool 265 into operative position. As shown in Fig. 11, the casing I26 has a channel 3&2 intersecting the longitudinal bore I2? at the left of the channel I25, and the channel 3% is connected bya pipe 393 to a channel 33% in the casing I28 for the valve I 22. Said channel 304 intersects an annular groove 3% in the casing I20 surrounding the valve I22 to the left of the channel are, and a channel 3% which intersects said annular groove is connected by a pipe 387 to a casing 308 in which a piston 3H3 is slidable. Fluid connection between the channel are and the channel 302 in the casing IZIS is normally cut oil by the full-size portion 395 of the valve I28, and fluid connection is provided between the channel 302 and an. exhaust channel MI in the casing I26 by a reduced portion 3i? of the valve IE8 at the left of the full-size portion 3M. The valve I28 has a full-size portion 3H2 to the left of the reduced portion 3I2.

When the valve I28 is shifted to the right by the movement of the depending arm 246 to the in the above cited Heald and Guild Patent No. r

1,779,094 so that, when fluid-under pressure is admitted to the casing-ace, the dressing tool is moved into operative position. On the return return of the table to operative position following the dressing operation, the full-size por-' tion 3M again cuts ofi the flow of fluid under pressure into the channel 302 and the reduced portion 3i2 provides fluid connection between the channel 362 and the exhaust channel 3H to permit return of the dressing tool to inoperative position.

The valve member I22 has a full-sized portion 3I3 at the left of the reduced portion I31 and an enlarged portion 3M at the left of the portion 3I3, said enlarged portion providing a shoulder 3I5 which is normally positioned within the annular groove 305. When fluid under pres sure passes from the channel 362 into the casing 308 by passing through the annular groove 3%,

I fluid under pressure acting on the shoulder M5 urges the valve member I22 to the left. Movement of the valve, however, is normally limited by the notch 298 in thelever 292 above referred to. When the lever 292 is rocked, during the extended movement of the table to the left, this rocking movement occurring while fluid under pressure is directed into the annular groove 305 by the valve I28, the end'of the valve is released from the notch 298 and said valve is allowed to move to the left.

Movement of the valve I22 to the left procures a throttling action on the fluid passing from the channel II 8 into the channel I23 so that the rate of travel of the table, during the remainder of the grinding operation, may be materially reduced. When the valve I22 reaches the left hand end of its movement, the right hand end of the reduced portion I31 of said valve partially closes the opening into the channel I23 from the bore I2I sothat, following the dressing operation when the valve I28 has been returned to the position shown in Fig. 11 to permit direct fluid connection from the channel I25 to the channel I96, thereby eliminating the auxiliary throttle valve I3I, the rate of movement of the table is controlled by the amount of fluid passing from the channel II8 into the channel I23, this amount of fluid being less than the throttled flow of fluid through the V-shaped notch 288 of the main throttle valve I9I. When the depending arm 246 is returned to the position of Fig. 1 during the return movement of the table to operative position, the valve I28 is returned to the position of Fig. 11 to render inoperative the auxiliary throttle valve .I3I.

After grinding is resumed, following the dressing operation, the crossfeed movement continues and the grinding wheel enlarges the bore of the workpiece until theflnish gage 224 is allowed to enter the bore of the workpiece. Entry of said gage provides an increased movement of the adjustable screw 238, secured to the gage structure, to the right to procure a further clockwise turning movement of the bell crank lever 262. This movement of the bell crank lever positions the horizontal arm 263 thereof in alinement with the upwardly extending end of anarm 3I6 of a lever 3| 1, Fig. 10, joumaled on the shaft 242 in back of the lever 24I. Said lever 3I1 has a depending arm or latch 3I8 which engages a notch 328 in a lug 32I on a depending arm 322 joumaled on the shaft 241 in back of the arm 246. Said arm 322 is urged to the right by a spring, not shown, directly in back of the spring 248 and engaging in a recess parallel to the recess 258 in the bracket 25L Clockwise turning movement of the lever 3I1, which occurs when the finish gage 224 enters the bore of the workpiece, elevates the arm 3I8 out of the notch 328 to permit the depending arm 322 to swing to'the right. This movement of the arm 322 procures a runout of the table to the rest position of Fig. 1 and a retraction of the crossfeed movement.

Referring again to Fig. 10, the depending arm 322 has a pin, not shown, which engages a devated sufllciently high to raise both of said dogs out of engagement with the lug I of the reversing member I3 so that the reversing valve is not shifted during movement of the table to the left,

and the latter moves beyond its operative position into the rest position of Fig. 1 where it is brought to rest by the fluid pressure mechanism above described.

'Movement of the arm 322 to the right also exhaust pipe 33I.

procures a shifting movement of the valve I22 to the right for procuring retraction of the crossfeed movement and for procuring a rapid movement of the table to the left into the rest position. The depending. arm 322 engages a groove 323' at the left hand end of the valve I22. When the valve I22 is shifted into the right hand position, fluid under pressure passes from the channel II8 around the reduced portion of said valve I31 into the channel I85 which, as above stated, is connected through the rectangular notch I94 of the throttle valve I8I to the reversing valve I8. Accordingly fluid under pressure free of any throttling action passes directly from the pump I8 to the reversing valve I8 and thence to the cylinder 25 so that the runout of the table to rest position occurs at the maximum rate of travel.

For retraction of the crossfeed movement, the valve I22 has a channel 324 therein which is open at one end to the reduced portion I31 of said valve and at the other end enters into an annular groove 325 formed in the full-size portion I85 of said valve. When the valve I22 is shifted intothe right hand position, at the end of the grinding operation, fluid under pressure from the channel II8 passes through the channel 324 into the groove 325 which is in alinement with the opening into the channel I41, thereby directing fluid under pressure through the pipe I45 and the connecting pipe I44 into the upper end of the cylinder H6 to procure a downward movement of the piston H5 and a corresponding retraction of the crossfeed movement.

The pipe I44 is connected by a branch pipe 326 to they upper end of a casing 321 in which a valve 328 is positioned. The casing 321 also has a port spaced from the pipe 326 and connected by a short pipe 338 to the pipe I68 from the casing I56 to the lower end of the cylinder II6. An exhaust port is also provided by the casing 321 and is spaced from the pipe connection 338, said exhaust port being provided with an exhaust pipe 33 I. The valve 328 which is normally maintained in the position shown by a coil spring 332 beneath said valve has an annular groove 333 substantially centrally thereof, and fluid connection from the pipe 338 to the exhaust pipe 33I is normally cut.

off by the full-size portion of the valve 328 below .said annular groove 333. When fluid under pressure is admitted through the pipe I45 and a branch pipe I44 into the cylinder 6 fluid under pressure also passes through the pipe 326 into the casing 321 above the valve member 328 urging said valve member downwardly and providing a fluid connection between the pipe 338 and the When this occurs, fluid is allowed to exhaust from beneath the piston 5 through the pipes I43 and I68'and the branch pipe 338 into the exhaust pipe 33I.

The shifting movement of the valve I22 also procures a retraction of the gage members from within the bore of the finished workpiece. As

shown in Figs. 3 and 11, the workhead is provided with a longitudinal bore 334 in which a piston 335 is movable. A piston rod 333 projects to the left beyond the workhead and engages the head of an adjustable screw 331 in the arm 221 of the gage mechanism, said screw being locked in position by a nut 338. The piston 335 is normally urged to the right to withdraw the piston rod 336 from engagement with the screw 331 by a spring 348, one end of which engages the piston 335 and the other end of which engages a cap 3 positioned over the end of the bore 334. The right hand end of the bore 334 base Port 342 connected 4' latter carries on the forward end thereof a plate by a pipe as, Fig. 11, to the pipe us; 'When fluid under pressure enters-the pipe I45 for retracting the crossfeed movement, fluid is also directed into the bore 334 to the right of the piston 335 urging the latter to the left against the ten- 345 secured against movement thereon, and said plate has an ejector arm 346 which extends transversely across the surface of the wheel 266 in spaced relation thereto, the arm being normally beneath the workpiece a as shown in Fig. 2. The plate 345, as shown in Fig. 2, has a slot 341 therein which receives-the end of the shaft 344 and a clamping nut 348 on. the end of the shaft 344 supports the plate in "adjusted position thereon. The left hand end of the shaft 344 has a bevel gear 356 secured against turning movement thereon, andsaid gear engages a bevel gear l secured against rotation on the upper end of a shaft 352 joumaled in a.

housing 353 secured to the table. An arm 354,

Figs. 4 and 5, secured against rotation on thelower end of the shaft 352 has a roller 355 on the end thereof which engages a cam 356 on a bracket 351 secured to the base of the machine. During the runout of the table to rest position, the cam 356 procures a turning movement of the shaft 352 and a corresponding clockwise rotation (Fig. 2) of the ejector arm 346 into the dotdash line position of Fig. 2. During this movement, the upper surface of the arm 346 engages the workpiece in the work-supporting structure and carries it around the periphery of the supporting wheel 266 to the top thereof where it is discharged toward the rear of the machine.

Referring again to Figs. 4 and 5, the shaft 344 carries a cam 358 adjacent the bevel gear 356, said cam engages a roller 366 on one end of a lever 36! joumaled on a pin 362 secured to the housing 353. The opposite end of the lever has a flat surface 363 which engages with one end of a bell crank lever 364 joumaled on the outer or left hand end of the shaft M5 to which the arm 214 carrying the pressure roller 213 is secured. The opposite arm 36 5 of the bell crank lever extends upwardly between the opposite legs 366 and 361 of a U-shaped member 368 secured against turning movement on the shaft 2I5. Set screws 316 and-3H are positioned in the legs 366 and 361 and engage opposite sides of thearm 365 to provide for adjustment of the bell crank lever 364 relative to the member 368. A rod 312, Figs. 1 and.5, extends upwardly from a lug 312" on the workhead through a notch, not shown, in the end of the bell crank lever 364. A spring 313 surrounds the pin and engages the upper surface of the bell crank lever to maintain the latterin engagement with the surface 363. The upper end of the spring 313 engages a threaded sleeve 314 which engages the upper threaded end of the rod 312. Turning movement of the sleeve 314 permits an adjustment of the tension of the spring 313, thereby varying the downward pressure on the bell crank lever 364 and accordingly adjustaoa'mer ing thepressure exerted bythe pressure wheel 2 I 3 eration, the workpiece (1' follows against the workpiece. During! turning movement of the shaft 344 for ejecting the workpiece, the cam 358 on said 'shaftrocks the lever 36! to procure a. clockwise movement (Fig. 5) of the bell crank lever 364 and a corresponding retraction of thepressure wheel 2l3 (counterclockwise, Fig.

2) from engagement with the workpiece toperq melt the workpiece to be easily elevated by the ejector from within the work-supporting member.

As shown inFig. 2, the table I has an upwardly extending portion 315 on which a bracket 316 is mounted, the latter having parallel slots 311 which areengaged by bolts 318 topermit adjustment of said bracket relative to the table. The

1, havinga bottom surface 38! inclined downwardly toward the rear, and the rearward end of the surface 38l is in substantially vertical alinement with the forward surface of the rotating and supporting roll 266 to permit workpieces positioned in the U-,shap ed groove 386 to drop into the work supportingmember. The bracket 316 15 A bracket 316 provides a U-shaped groove 386;.Fig.

also provides an arcuate U-shaped groove 382 substantially parallel to the periphery of the roll 266 and in alinement withthe workpiece a in. the work-supporting member, said groove extending from a point slightly above the workpiece to a point directly above the upper position of the ejector arm and intersecting the groove 386.

The workpieces in the groove 386 are normally urged by gravity toward the rear into the position shown in Fig. 2 and are prevented from passing beyond the position shown by-an arm 383 which engages the bracket 38! in alinement with the workpieces in the groove 386. Thearm 383 is'se-.

cured against rotation on a shaft 384 journaled in a bracket 384' mounted on the workhead and said shaft has a horizontally extending arm 385 which engages the upper end of a vertical plunger 386 in a sleeve 381 provided by the bracket 384'. A

cam 388 secured to the shaft 344 between the plate 345 and the roll 266 engages, during the rotation of the shaft 344, with the lower end of the plunger 386urging the latter upwardly to procure a clockwise turning movement of the arm 383, thereby releasing the rearmost workpiece in the groove 386. A depending arm 385' secured to the shaft 384 engages-a spring 396 which is positioned between the sleeve 381 and said arm and which retains the arm 383 in the normal position shown.

The ejector arm 346, as shown in Figs. 2 and 4,

is of a sufficient width to prevent the rearmost workpiece a in the groove386, when released by the arm 383, from dropping between the groove 382 and, the roll 266 beneathsaid ejector arm. As the ejector arm returns counterclockwise to the position shown in full lines in Fig. 2, this movement occurring as the workheadmoves into operative position for a subsequent grinding opsaid arm downwardly, guided by the groove 382, so that said workpiece is properly positioned in the work-supporting member in readiness for .a grinding operation thereon.

As above stated, the finished workpiece is discharged when theejector reaches the upper dotdash line position of Fig. 2. From this position, the finished workpiece rolls by gravitytoward the rear of the machine over a guide 3! secured to the workhead and having a downwardly and rearwardly inclined surface 382 at its upper end. The forward edge of the surface 392 is positioned close to the periphery of the roll 266 so that the finished workpiece passes over the surface 392 and onto a surface 393 provided by the end of an arm 394 journaled on a stud 395 positioned in a rearwardly extending portion 396 of the bracket 384'. The portion 396 provides a rearwardly and downwardly inclined surface 391, the forward edge of which is normally positioned above the surface 393 a suflicient distance to stop the rearward movement of the discharged workpiece so that the rapid movement of the latter resulting from the action of the ejector arm 346 is checked and the workpiece is brought to rest in the dot-dash line position shown.

The arm 394 has a downwardly projecting arm 398 which has a roller v400 on the outer end thereof in alinement with a cam 40l on a guard 402 projecting upwardly from the base of the machine at the rear thereof. After the workpiece reaches the position shown in dotted lines above the surface 393, the arm 394 is rocked upwardly by the cam 40| during the movement of the table to rest position, thereby lifting the surface 393 into alinement with the surface 391 to allow the workpiece to roll slowly down the surface 391 and be discharged.

To make the grinding machine entirely auto matic and to avoid the necessity for manual starting of the machine for each successive grinding operation, the table carries a block 403 which is provided with a cam'member 404 in alinement with the upper end of the upwardly projecting arm 255. As the table moves to the left and just before the table reaches the rest position shown, the cam member 404 rocks the arm 255 downwardly a small amount to permit a depending dog 405 on the block 403 in back of the cam member 404 to engage with the upwardly extending portion 2' of the reversing lug I5, thereby reversing the table movement and procuring a return of the workhead to operative position. Since the portion 323' of the valve I22 is wider than the lower end of the arm 322 engaging therewith, the'slight turning movement of said arm resulting from the downward movement of the arm 255 by the cam 404 does not lever 262 counterclockwise for returning said lever to the original position shown, in readiness for a clockwise'turning movement in response to entry of the gages within the bore of the workpiece during the subsequent grinding operation.

The operation of the machine which will doubtless be clear from the foregoing description will be briefly'summarized. With the table at the end of its extended movement, as shown in Fig. 1, the ejector arm is in the dot-dash line position of Fig. 2 and the arm 363 is also in the dot-dash line position to permit the rearmost workpiece in the groove 360 to roll rearwardly onto the surface of the ejector arm 346. At this time, the finished workpiece has been descharged, bythe upward movement of the ejector, to the dot-dash line position indicated, and the arm 2 I 4 carrying the pressure roll 2 I3 has been rocked counterclockwise (Fig. 2) to permit the finished workpiece to be discharged from the work-supporting structure and the unground workpiece to be properly positioned within said structure. The valve member I26 at this time is in the position of Fig. 11, into which position it was moved directly following the dressing operation during the preceding grinding operation, and the valve member I 22 is in the extreme right hand position into which it was shifted at the end of the preceding grinding operation.

Assuming that the table has been brought to rest by turning of the throttle valve I9I to cut off the flow of fluid from the pipe I66 into the pipe I63 and also from the pipe I91 into the pipe I93, movement of the table to the right for positioning the workhead in operative relation to the grinding wheel is procured by turning said throttle valve I9I by means of thelever 204 on the front of the control box. Fluid under pressure is then directed from the pump through the pipes III and I86 and through the notch I94 of the throttle valve to the left hand end of the cylinder 26, the reversing valve having previously been shifted, by the reversing dog'405, from the position shown into its opposite position in which fluid connection is provided between the ports I1 and 22 of the valve casing. The table then moves to the right into operative position at the maximum rate of speed.

During the movement of the workhead to operative position, the ejector arm 346 is swung counterclockwise and the workpiece a follows said ejector arm downwardly in the groove 382 of the bracket 316 until it reachesthe proper grinding position in engagement with the regulating wheel 206 and the supporting roll 201; The ejector arm continues downwardly into the full line position of Fig. 2 where it remains'during the entire grinding operation. The turn ing movement of the ejector arm which is responsive to movement of the table also permits the pressure roller 2I3 to be returned to operative engagement with the workpiece by the spring 313 which resiliently retains said roller against the workpiece.

During the movement of the workhead into operative position, the depending dog 2'12 engages the upwardly extending arm 255 and rocks said arm downwardly, thereby returning the depending arms 246 and 322 to the original positions of-Fi8. 1. tained at their extreme left hand end of movement by fluid under pressure in the bore 334, the lovers 24I and 3|! are free to move so that the latches 243 and 3I3 of said levers engage the notches on the depending arms and retain them in their original position. During the return movement of the arm 246 to original position, the latch 215 is released to permit a subsequent movement of the arm 246 to the right, and the lever 262 returns to the position of Fig. 1 for limiting the left hand movement of the valve I22 during the subsequent grinding operation.

Return of the depending arm 322 to original position shifts the valve I22 to the mid-position of Fig. 11, thereby cutting off the flow of fluid through the pipe I66 and directing fluid under pressure through the pipes I24 and I91 to the throttling notch 200 of the reversing valve so that the movements of the table in operative position occur at a rate determined by the setting of the valve I9I. Movement of the valve I22 to mid-position also permits fluid from the bore 334 to exhaust and also provides for exhaust of fluid from the upper end of the cylinder IIB. When the pipe I45 communicating with the upper end Since the gage members are still reaoamav of the cylinder H6 is connected to the exhaust, the valve 323-returns to the position of Fig. 11, thereby directing fluid under pressure through the pipe I43 to the lower end of the cylinder H6 and the cros'sfeed movement is started, this crossfeed movement occurring at the rate determined by the setting of the valve I60.

The workpiece in the workhead having reached operative position, it is reciprocated axially over the surface of the grinding wheel under the control of the dogs 8 and I with thegage member 223 attempting on each reciprocation to enter the bore of the workpiece, said gage being urged to the right by the spring 235. Grinding continues with the workpiece reciprocating over the grinding wheel and with the crossfeed movement occurring at the rough grinding rate determined by the setting of the valve I60 until the roughing gage 223 enters the bore of the workpiece, thereby rocking the lever 24I to procure an upward movement of the arm 255 and a corresponding movement of the, depending arm 246 to the right. Upward movement of the arm 255 renders inoperative the reversing dog I0 for an extended movement of the table to the left for a dressing operation on the grinding wheel. The movement of the arm 246 to the right shifts the valve I28 to the right, thereby reducing the rate of movement of the table by directing fluid auxiliary throttle valve the flow of fluid to the under pressure past the I3I. At the same time,

cylinder H8 is temporarily out off-by the'valve I28 so that no crossfeed movement occurs during the dressingopration.

During the extended movement for dressing, the lever 292 is rocked to permit-the valve I22 to move to its left hand position and at the same time to position said lever to engage with the latch 215. The movement of the valve I22 to the left limits the flow of fluid under pressure into the pipe -I24 for reducing the rate of reciprocation of the table during the remainder of the grinding operation.

The extended movement of the table for dressing is reversed by the dog 26! and during the return movement, the depending dog 212 returns the arm 255 to original'position, thereby preventing a repetition of the dressing operation, and also returns the depending arm 246 to original position where it is retained by the latch 215. Return of the arm 246 also returns the valve I28 to the position of Fig. 11 so that fluid under pressure again enters the cylinder IIB for continuing the crossfeed movement.

At a predetermined time during the grinding operation, the cam I08 urges the valve Hi3 down-, wardly to cut off the flow of fluid through the throttle valve I60 so that'the remainder of the crossfeed movement occurs at a slower or finish grinding rate as determined by the setting of the throttle valve I12.

Following the dressing operation, the grinding operation continues until the flnish gage 224 enters the bore of the workpiece, thereby rocking the lever 3I'I to permit the depending arm 322 i to swing to the right, thus elevating the arm 255. Elevation of the arm 255 renders the dogs I0 and 261 both inoperative for an extended movement of the table to the left. Movement of the depending arm 322 to the right shifts the valve I22 to its extreme right hand position, thereby directing fluid under pressure to the upper end of the cylinder I6 for a retraction of the crossfeed movement during which movement the cam I08 is withdrawn from engagement with the valve cam member 404 rocks the arm to permit the depending dog to actuate the re-,

member. I63 to permit the latter to return to original position. The valve I22 also directs fluid under pressure 'to the casing 321 for urging the valve 320 downwardly, thereby connecting the lower end of. the cylinder H6 to the exhaust pipe 33I, and also directs fluid under pressure to the bore 334 for retracting-the gages 223 and 224 to the extreme left hand position of Fig. 3 out of the bore of the workpiece. Fluid under pressure is also directed by the valve I22 through the pipe l80.to the reversing valve so that the extended movement of the table to the left occurs at the maximum rate of speed.

During the extended movement of the table afterthe completionof the grinding operation, the ejector arm 343 is rocked clockwise (Fig. 2)

for carrying theqflnished workpiece upwardly piece reaches the dot-dash line position, elevates the arm 394 to bring the surface 303 into-alincment with the surface so that the workpiece is discharged from the machine. Before the ejector arm 346 moves into engagement with' the finished workpiece during'its upward movement, the pressure roll H3 is rocked; counterclockwise '(Fig. 2) through the medium .of .the cam 353 on the 'ejector'sha'ft'. As the ejector reaches its upper or dot-dash line position,xthe' arm 383is raised to permit the rearmost wor-kpiece inthe groove 300 to roll onto the surface'of said ejector as above stated.

As the table reaches the position of Fig. 1, the 255:downward1y versing member I3, thereby reversing the table movement and returning the workhead to operative position. The grinding operation is then repeated in the manner above outlined.-

The ejector and the workloading structure is arranged for use with a plurality of similar workpieces which are to be ground simultaneously in the machine. It will be apparent from a consideration of Figs. 1 to 4 inclusive that the single workpiece shown might as easily consist of a plurality of workpieces of less length. In this case, the ejector arm 343which, as shown in Fig. 4, extends across the entire outer surface of the regulating wheel 206 will engage beneath each of the workpieces for carrying. all of them as a unit upwardly in the groove 332, said groove acting to retain said workpieces in position on the surface of the ejector arm 346 during their upward movement. As shown in Fig. 2, the lower end of the bracket 310 projects downwardlyv be noted that the gage members are retained to the left within the annular flange of the backing plate during the time'that the ejector mechanism is discharging the finished workpiece and directing the unground workpiece into proper positionwithin the, supporting structure.

We claim,

1. In apparatus of the class described, a worksupporting structure comprising a rotating drive wheel engaging with the periphery of a workpiece, a supporting member engaging said work piece, a pressure member resiliently engaging said workpiece for holding said workpiece in engagement with the drive wheel and the support, and a backing plate engaging the workpiece to prevent axial movement thereof in the work-supporting structure, and a plug gage member axially slidable within the backing plate for entry within the bore of the workpiece when the latter reaches a desired size. 2. In a grinding machine, a grinding member and a work-supporting member, a table onwhich one of said members is mounted, means operable during the progress of the grinding operation for procuring a movement of the table for a dressing operation on the grinding member, hydraulically actuated means independent of the table moving means for procuring a cros'sfeed movement between said members, and means for discontinuing the orossfeed movement during the dressing operation.

3. In a grinding machine, a grinding member and a work-supporting member, means, includoperation. 70

ing a piston and cylinder, for procuring a crossfeed movement between said members, means operable during the grinding operation for procuring a dressing operation on the grinding member, and valve means actuated in response to said last means for discontinuing the flow of fluid under pressure to said crossfeed means during the dressing operation.

4. In a grinding machine, a grinding member and a work-supporting member, hydraulically actuated means for procuring a crossfeed movement between said members, and means under the control of said crossfeed movement for reducing the flow of fluid to said hydraulically actuated means, thereby diminishing the rate of said crossi'eed movement.

5. In a grinding machine, a grinding member and a work-supporting member, hydraulically actuated means for procuring a cro-ssfeed movement between said members, and valve means actuated in response to the cross-feed movement for reducing the flow of fluid to the hydraulically actuated means for diminishing the rate of said crossfeed movement.

6. In a grinding machine, a grinding member and a work-supporting member, hydraulically actuated means for procuring a crossfeed movement between said members, said means including a piston and cylinder, means for directing fluid under pressure to one end of said cylinder at a predetermined rate, means operable during the grinding operation for procuring a dressing operation on the grinding member, and valve means for cutting oiT the flow of fluid to said cylinder during the dressing operation.

7. In a grinding machine, a grinding member and a work-supporting member, hydraulically actuated means for procuring a cross-feed movement between said members, said means includinga piston and cylinder, means for directing fluid under pressure to one end of said cylinder at a predetermined rate, means operable during the grinding operation for procuring a dressing operation on the grinding member, and valve means automatically operable for cutting oif the flow of fluid to said cylinder during the dressing 8. In a grinding machine, a grinding member and a work support ng member, hydraulically actuated means for procuring a crossfeed movement between said members, said means including piston and cylinder elements, one of said elements having a predetermined limited movement, means for procuring a retraction of the crossfeed movement at the completion of a grinding operation, and means automatically operable during the retraetive movement for compensating for the wear on the grinding member.

9. In a grinding machine, a grinding member and a work-supporting member, hydraulically actuated means for procuring a crossfeed movement between said members, said means including piston and cylinder elements, one of said elements having a predetermined limited movement, means for procuring a dressing operation on the grinding member during the grinding operation, means for procuring a retraction of the crossfeed movement at the completion of a grinding operation, and means automatically operable during the retracting movement for compensating for the wear on the grinding member.

10. In a grinding machine, a grinding member and a work-supporting member, means for procuring a crossfeed movement between said members, said means including a piston and cylinder, means for directing fluid under pressure to one end of said cylinder, manually adjusted throttle valves for controlling the amount of fluid under pressure entering said cylinder during the grinding operation, and means under the control of the crossfeed movement for rendering one of said throttle valves inoperative and for procuring a change in the rate of crossieed movement.

ll. In a. grinding machine, a grinding member and a work-supporting member, means for procuring a crossfeed movement between said members, said means comprising a cross-slide on which one of said memmrs is mounted, a crossfeed screw for actuating said slide, a piston and cylinder, one of which is connected to the crossfeed screw for rotating said screw, means for directing fluid under pressure at a predetermined rate to one end of said cylinder for advancing said members relative to each other at a predetermined rate, and means for procuring a change in the rate of crossfeed movement in response to said movement.

12. In a grinding machine, a grinding member and a work-supporting member, means for procuring a crossfeed movement between said members, said means comprising a cross-slide on which one of said members is mounted, a crossieed screw r for actuating said slide, a piston and cylinder, one of which is connected to the crossfeed screw for rotating said screw, means for directing fluid under pressure at a predetermined rate to one end of said cylinder for advancing said members relative to each other at a predetermined rate, means for procuring a change in the rate of crossfeed movement in response to said movement and means-operable when a workpiece in the work-- sequent downward movemenl, directing an unground workpiece into the work-supporting member.

14. In a grinding machine, a grinding member and a work-supporting member, the latter comprising a rotatable regulating wheel engageable with the workpiece in said member, a support, and a pressure member for resiliently holding the workpiece in engagement with said wheel and support, an ejector normally extending beneath the workpiece in the supporting member, and means operable upon the completion of the grinding operation for rocking said ejector arm'upwardly to discharge the workpiece radially "from the supporting member, said ejector arm, during its subsequent downward movement, directing an unground workpiece in the work-supporting member.

15. In a grinding machine, a grinding member and a work-supporting member, the latter comprising a rotatable regulating wheel engageable with the workpiece in said member, a support'and a pressure member for resiliently holding the workpiece in engagement with said wheel and support, an ejector normally extending beneath the workpiece in the supporting member, means, operable upon the completion of the grinding operation for rocking said ejector arm upwardly to discharge the workpiece radially from the supporting member, and other means operable at the completion of the'grinding' operation for spacing the pressure member from the workpiece to permit discharge of the workpiece from the worksupporting member.

' 16.-'In a grinding machine, a grinding member and a work-supporting member, the latter comprising a rotatable regulating wheel engaging the periphery of a workpiece in said member, a support engaging the periphery of said workpiece beneath the axis thereof, a pressure wheel for resiliently urging said workpiece into engagement with the regulating wheel and-support, a table on which one of said members is mounted, means for procuring an. extended movement of said table for an axial separation between said members when the workpiece in the work-supporting member reaches the desired size, and an ejector normally positioned below said workpiece and actuated directly in response to movement of the table for removingtlhe finished workpiece from the work-supporting member and for directing an unground workpiece into said work-supporting member.

17. In a grinding machine, a grinding member and a work-supporting member, the latter comprising a rotatable regulating wheel engaging theperiphery of a workpiece in said member, a support engaging the periphery of said workpiece beneath the axis thereof, a pressure wheel for resiliently urging said workpiece into engagement with the regulating wheel and support, a table on which one of said members is mounted, means for procuring an extended movement of said table for an axial separation between said members when the workpiece in the work-supporting member reaches the desired size, an ejector normally positioned below the workpiece, and means actuated directly in response to movement of the table and operative during said movement for rocking said ejector'upwardly to discharge the finished workpiece and for separating the pressure member from said workpiece.

l8. Ina grinding machine, a grinding member and a work-supporting member, the latter comprising a rotatable regulating wheel engaging the periphery of a workpiece in said member, a support engaging the periphery of. said workpiece beneath the axis thereof, a pressure wheel for resiliently urging said workpiece into engagement with the regulating wheel and support, a table on which one of said members is mounted, means for procuring an extended movement of said table for an axial separation between said members when the workpiece in the work-supporting member reaches the desired size, an ejector normally positioned below the' workpiece .and turnable about the axis of the regulating wheel, and a bracket-having an 'arcuate groove corresponding substantially in shape to the periphery of the regulating wheel, being ispaced therefrom and positioned above the workpiece, the finished workpiece passing upwardly through said groove as the ejector is rocked upwardly, said groove guiding an unground workpiece downwardly during the return of the ejector to normal position.

19. In a grinding machine, a grinding member and a work-supporting member, the latter comprising a rotatable regulating wheel engageable with the periphery of a workpiece, a work-support beneath said workpieceand a pressure member engaging the periphery of said workpiece and resiliently retaining the latter in engagement with said wheel and support, an ejectorfor discharging the finished workpiece radially from the discharge of the finished workpiece and'the positioning of an unground workpiecein the'worksupporting member.

20. In a' grinding machine, a grinding member 1 and a work supportingmember, the latter comprising a rotatable regulating wheel engageable with the periphery of a workpiece, a work-support beneath said workpiece and a pressure member engaging the periphery of said workpiece and resiliently retaining the latter in engagement with said wheel and support, a table on which one of said members is mounted, means operable at the completion of a grinding operation for procuring an' extended movement of the, table for an axial separation between said member, and an ejector having an arm thereof extending beneath the workpiece and parallel to the periphery of the regulating wheel, said ejector being .rocked upwardly in response to the extended i movement for radial discharge of the finished workpiece.

21. In a machine for the successive reduction of workpieces to a predetermined size, a grinding member and a work-supporting member, hy-

draulically actuated means for procuring a crossfeed movement between said members, an ejector normally positioned beneath the workpiece in the work-supporting member, automatically operable means for rocking said ejector upwardly for dismined size, a grinding member and a work-supporting member, a table on which one of said members is mounted, hydraulically actuated means for procuring a crossfeed movement between said members, means operable when the work-piece in v the work-supporting member reaches the desired size for procuring an extended movement of the table for an axial separation between said members, an ejector normally positioned beneath the workpiece in the worksupporting member and actuated in response to said extended movement for discharging the iinished workpiece and positioning an unground workpiece in the work-supporting member, and means responsive to the table movement for reversing the table at the end of the extended movement.

23. In a machine for successive reduction of a plurality of workpieces all to the same predetermined size, a grinding member and a work-supporting member, a table on which one of said members is mounted, hydraulically actuated means for procuring a crossieed movement between said members, size-determining means, means responsive to said size-determining means for procuring an extended movement of the table, a valve member actuated by said size-determining means for procuring reversal of the crossteed movement and retraction of the size-determining means from the bore of the workpiece, an ejector for discharging the finished workpiece from the work-supporting member and for positioning an unground workpiece therein; means for reversing the table at the end of the extended movement,

and means operable during the return of saidtable to operative position for resetting said valve member to permit the size-determining means to engage the workpiece in the work-supporting member and to procure the crossfeed movement.

24. In a grinding machine, a grinding member and a work-supporting member, the latter comprising a rotatable regulating wheel engageable with the workpiece in said member, a work support, and a' pressure member for resiliently holding the workpiece in engagement with said wheel and support, an ejector normally extending beneath the workpiece in the supporting member, means operable'upon. the completion of the grinding operation for rocking said ejector arm upwardly to discharge the workpiece radially from the supporting member and for spacing the pressure member from the workpiece to permit discharge of said workpiece, a gage member whose entry within the bore of the workpiece indicates the completion of the grinding operation, and means automatically operable prior to operation of the ejector actuating means for retracting said gage from within the bore of the workpiece.

25. In a grinding machine, a grinding member and a work-supporting member, the latter comprising a rotatable regulating wheel engageable with the workpiece in said member, a work support, and a pressure member for resiliently holding the workpiece in-engagement with said wheel and support, a gage member whose entry within the bore of the workpiece procures an axial separation of the grinding member from the workpiece, an ejector normally extending beneath the workpiece in the supporting member, means operable upon the completion of the grinding operation and in response to said axial separation for actuating said ejector arm to discharge I 

